Cosmetic composition

ABSTRACT

The invention provides a cosmetic composition, particularly a cosmetic composition for antiperspiration. The invention relates to a cosmetic composition comprising surface-hydrophobated water-absorbing polymer particles and an anti-perspiring component, as well as a cosmetic composition comprising water-absorbing polymer particles, an anti-perspiring component, and at least one member selected from the group consisting of silicone having a viscosity (25° C.) of not higher than 5×10 −3  m 2 /s and hydrophobic particles, wherein the content of the water-absorbing polymer particles is 3 to 95 parts by weight relative to 100 parts by weight of the anti-perspiring component.

FIELD OF THE INVENTION

The present invention relates to a cosmetic composition useful forantiperspiration.

BACKGROUND OF THE INVENTION

In perspiring sites particularly the armpit, stickiness due toperspiration worsens the skin feel and an unpleasant smell is generated,and thus cosmetics having an anti-perspiring effect have been used.Particularly, an aluminum compound is used as a main componentexhibiting an anti-perspiring effect (JP-A 52-99236). However, stickyfeel due to perspiration remains, and the anti-perspiring effect is notsufficient.

In order to reduce sticky feel due to perspiration, accordingly,cosmetics containing an anti-perspiring component and/or a sterilizingcomponent and a highly water-absorbing polymer compound (JP-A 3-284617),and then cosmetics containing a novel aluminum compound as ananti-perspiring component have been known, but their anti-perspiringeffect are not sufficient, and stickiness due to perspiration are oftenfelt.

Further, when an antiperspirant based on an aluminum compound is appliedonto the armpit and soap foam is applied onto the armpit at the time ofshaving, the foam is broken thus causing not only a problem ofdeterioration in smoothness upon shaving with a razor, but also aproblem that owing to components in the antiperspirant, soap scum isformed in a large amount in the armpit, to further deterioratesmoothness upon shaving with a razor.

Further, cosmetics containing hydrophobated powder and a water-absorbingpolymer (JP-A 4-356415) are known in order to reduce sticky feel due toperspiration.

SUMMARY OF THE INVENTION

The present invention relates to a cosmetic composition, particularly acosmetic composition for antiperspiration.

The present invention provides a cosmetic composition containingsurface-hydrophobated water-absorbing polymer particles and ananti-perspiring component.

The present invention provides use of a composition containingsurface-hydrophobated water-absorbing polymer particles and ananti-perspiring component as cosmetics. The present invention alsoprovides a method of antiperspiration, which includes applying acomposition containing surface-hydrophobated water-absorbing polymerparticles and an anti-perspiring component onto the skin.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a cosmetic composition having highanti-perspiring performance and excellent in smoothness at the time ofshaving. The present invention provides a cosmetic compositionpreferably containing water-absorbing polymer particles, ananti-perspiring component, and at least one member selected from thegroup consisting of silicone having a viscosity (25° C.) of not higherthan 5×10⁻³ m²/s and hydrophobic particles, wherein the content of thewater-absorbing polymer particles is 3 to 95 parts by weight relative to100 parts by weight of the anti-perspiring component.

[Water-Absorbing Polymer Particles]

The shape of the water-absorbing polymer particles in the presentinvention is not particularly limited, and may be not only in the formof sphere, egg or lump, but also in the form of scale, plate, fiber,fine-powder agglomerate (granule) or in an amorphous state. Preferably,the water-absorbing polymer particles are in the form of sphere, egg orlump for easy availability, more preferably in the form of sphere forgood feeling. These particles may be porous.

When the water-absorbing polymer particles used in the present inventionare in the form of sphere, egg or lump, the average particle diameterthereof is preferably 0.1 μm or more, more preferably 0.5 μm or more,and the upper limit is preferably 50 μm or less, more preferably 20 μmor less, still more preferably 10 μm or less and even more preferably 5μm or less, so that the resulting cosmetics are not remarkable as whitepowder, do not cause a sense of incongruity after absorption of water,have dry feel, and are not easily removed from the skin. The averageparticle diameter refers to the diameter of a particle not swollen withwater, determined (in a cyclohexane solvent) with a light scatteringparticle-diameter measuring instrument (for example, LS-230 modelmanufactured by Coulter, Inc.).

The amount of water absorbed into the water-absorbing polymer particlesused in the present invention is preferably not lower than 5 g/g, morepreferably not lower than 10 g/g, to achieve sufficient anti-perspiringperformance, and the upper limit is preferably not higher than 100 g/g,more preferably not higher than 50 g/g, still more preferably not higherthan 30 g/g, in order to prevent the particles from giving slimy feelupon absorption of sweat on the skin and to make them hardly releasablefrom the skin. The amount of water absorbed can be determined by adding1000 ml water to 5 g sample, then suspending and stirring it for 30minutes (100 rpm, 25° C.), centrifuging it at 2,000 G for 30 minutes,discarding the supernatant gently, measuring the weight of the sample,and determining the amount of water absorbed, on the basis of thedifference of this weight from the initial weight of the sample.

As the polymer used in the water-absorbing polymer particles of thepresent invention, a natural polymer, a semi-synthetic polymer or asynthetic polymer can be used insofar as it is a polymer having theaction of absorbing water. To attain a water-retaining property, it ispreferably a polymer having a crosslinked structure, and such a polymeris a (co)polymer crosslinked by a crosslinking method described later ora (co)polymer having a crosslinkage via a hydrogen bond or hydrophobicbond, a crosslinkage derived from a partial crystalline structure or acrosslinkage derived from a helix structure etc. [(co)polymer means apolymer or copolymer.].

For example, the natural polymer and semi-synthetic polymer includestarch, carrageenan, gelatin, agar, tragacanth gum, viscose, cellulose(for example, crystalline cellulose), methyl cellulose, ethyl cellulose,hydroxyethyl cellulose and carboxymethyl cellulose, or crosslinkedproducts thereof, for example starch-(meth)acrylate graft copolymers (orits crosslinked products) [(meth)acrylate means acrylate, methacrylateor a mixture thereof.].

The synthetic polymer includes a crosslinked product of a (co)polymer ofhydrophilic vinyl monomers such as anionic monomers or salts thereof,nonionic hydrophilic group-containing monomers, amino group-containingunsaturated monomers or neutralized products thereof or quaternarizedproducts thereof. The hydrophilicity of the hydrophilic vinyl monomermeans that the solubility in 100 g of water (20° C.) is preferably 6weight % or more, more preferably more than 20 weight %. Examples ofmonomers used in production of the synthetic polymer include anionicmonomers such as (meth)acrylic acid, maleic acid, fumaric acid, crotonicacid, itaconic acid, 2-(meth)acryloyl ethane sulfonic acid,2-(meth)acryloyl propane sulfonic acid, 2-(meth)acrylamide-2-methylpropane sulfonic acid, vinyl sulfonic acid and styrene sulfonic acid orsalts thereof; nonionic hydrophilic group-containing monomers such as(meth)acrylamide, N-substituted (meth)acrylamide,2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate,methoxypolyethylene glycol(meth)acrylate, polyethyleneglycol(meth)acrylate, N-vinyl pyrrolidone and N-vinyl acetamide; andamino-group containing unsaturated monomers such asN,N-dimethylaminoethyl(meth)acrylate,N,N-dimethylaminopropyl(meth)acrylate andN,N-dimethylaminopropyl(meth)acrylamide or acid-neutralized productthereof, or quaternized products thereof. Preferable examples of theacid used in producing the acid-neutralized product include hydrochloricacid, sulfuric acid, nitric acid, acetic acid, formic acid, maleic acid,fumaric acid, citric acid, tartaric acid, adipic acid, lactic acid etc.,and preferable examples of the quaternizing agent include alkyl halidessuch as methyl chloride, ethyl chloride, methyl bromide and methyliodide, and standard alkylating agents such as dimethyl sulfate, diethylsulfate and di-n-propyl sulfate. The counterion includes halogen ionssuch as chlorine and organic anions such as methosulfate. Unless thehydrophilicity of the resultant polymer is extremely inhibited, thehydrophobic vinyl monomers such as acrylates and styrene or derivativesthereof can also be simultaneously copolymerized in an amount ofpreferably 0 to 50% by weight, more preferably 0 to 20 weight %, of thetotal monomers.

The hydrophobicity of the hydrophobic vinyl monomer means that thesolubility in 100 g of water (20° C.) is preferably less than 6 weight%. No lower limit is provided. It may be 0.01 weight % or more.

As the monomer components used, one or more of those enumerated abovecan be selected, but crosslinked (co)polymers of α,β-unsaturatedcarboxylic acid monomers such as (meth)acrylic acid, maleic acid,fumaric acid, crotonic acid, itaconic acid or salts thereof arepreferable because of their high water-absorbing ability and easyavailability. In addition to the α,β-unsaturated carboxylic acidmonomers, other monomers can also be copolymerized.

To improve the water-absorbing ability, the amount of the hydrophilicvinyl monomers blended is preferably at least 50% by weight, morepreferably at least 70% by weight and particularly preferably at least90% by weight of the total monomers constituting the water-absorbingpolymer particles.

The water-absorbing polymer particles are preferably a crosslinkedpolymer or copolymer of hydrophilic vinyl monomers and/or salt thereof,more preferably a crosslinked polymer or copolymer of α,β-unsaturatedcarboxylic acid monomers and/or salts thereof, particularly preferablycrosslinked poly(meth)acrylate. These water-absorbing polymers can beused alone or in combination thereof.

The “salt” includes e.g. alkali metal salts (sodium salt, potassiumsalt, lithium salt etc.), alkaline earth metal salts (calcium salt,magnesium salt, barium salt etc.) and ammonium salts (quaternaryammonium salt, quaternary alkyl ammonium salt etc.). Among these, thesodium salt is even more inexpensive and preferable. Here, the degree ofneutralization of the water-absorbing polymer particles is preferably0.01 to 100%, more preferably 1 to 99% and particularly preferably 40 to95% based on the number of moles of the acid group in thewater-absorbing polymer. In the present invention, the “degree ofneutralization” refers to the ratio (on a molar basis) of thesalt-forming acid group to the acid group in the water-absorbingpolymer, that is, (number of moles of the salt-forming acidgroup)/(number of moles of the salt-formable free acid plus thesalt-forming acid group)×100 (%).

The method of forming the crosslinked (co)polymers described aboveinvolves covalent crosslinking by (a) self-crosslinking duringpolymerization, (b) copolymerization with a multifunctional monomer, and(c) irradiation with radiation, or ionic crosslinking via (d) polyvalentmetal ion. Among these, (b) is preferable from the viewpoint of easyproduction and stability of the crosslinked structure, and themultifunctional monomer includes a crosslinking vinyl monomer having atleast 2 reactive unsaturated groups in the molecule and a compoundhaving at least 2 functional groups other than unsaturated groups in themolecule (the above crosslinking vinyl monomer and the above compoundare referred to collectively as crosslinking agent)

Among these crosslinking vinyl monomers having at least 2 reactiveunsaturated groups in the molecule, ethylene glycol di(meth)acrylate,polyethylene glycol di(meth)acrylate, divinyl benzene, pentaerythritoltriallyl ether, pentaerythritol tetraallyl ether, and methylenebisacrylamide are preferable.

The compound having at least 2 functional groups other than unsaturatedgroups in the molecule is more preferably ethylene glycol diglycidylether or polyethylene glycol diglycidyl ether.

The amount of the crosslinking agent added is varied depending on thetype of the crosslinking agent and the crosslinking method, but ispreferably 0.001 part by weight or more, more preferably 0.01 part byweight or more, particularly preferably 0.1 part by weight or more,relative to 100 parts by weight of the total monomers constituting thewater-absorbing polymer particles, and the upper limit is preferably 20parts by weight or less, more preferably 10 parts by weight or less,particularly preferably 5 parts by weight or less. When the amount ofthe crosslinking agent is 0.001 part by weight or more, the amount ofwater absorbed can be maintained due to a lower content of water-solublecomponents in the resulting water-absorbing polymer, while when itsamount is 20 parts by weight or less, the density of crosslinkages issuitable and the amount of water absorbed into the resultantwater-absorbing polymer is sufficient.

The water-absorbing polymer particles used in the present invention arepreferably water-absorbing polymer particles wherein at least a part ofthe surfaces of water-absorbing polymer particles was hydrophobated(referred to hereinafter as surface-hydrophobated water-absorbingpolymer particles).

Such surface-hydrophobated water-absorbing polymer particles include,for example, (1) surface-hydrophobated water-absorbing polymer particleswherein the surfaces of water-absorbing polymer particles were coatedwith a silicone compound having at least one kind of functional group,(2) surface-hydrophobated water-absorbing polymer particles wherein thesurfaces of water-absorbing polymer particles were coated with a polymerof a hydrophobic vinyl monomer, (3) surface-hydrophobatedwater-absorbing polymer particles wherein the surfaces ofwater-absorbing polymer particles were treated with a fluorine-basedsurfactant, and (4) surface-hydrophobated water-absorbing polymerparticles wherein the surfaces of water-absorbing polymer particles weretreated with a silane coupling agent. Among these polymer particles, thesurface-hydrophobated water-absorbing polymer particles wherein thesurfaces of water-absorbing polymer particles were coated with asilicone compound having at least one kind of functional group arepreferable. Hereinafter, preferable surface-hydrophobatedwater-absorbing polymer particles are specifically described.

(1) Surface-hydrophobated water-absorbing polymer particles wherein thesurfaces of water-absorbing polymer particles were coated with asilicone compound having at least one kind of functional group

The silicone compound having at least one kind of functional group is asilicone compound having at least 2 silicon atoms, having at least onekind of functional group capable of chemical bonding, preferablycovalent bonding and/or ionic bonding, to the surfaces ofwater-absorbing polymer particles.

In the surface-hydrophobated water-absorbing polymer particles, thesurfaces of the water-absorbing polymer particles have been coatedpreferably via chemical bonding with a silicone compound having at leastone kind of functional group. The silicone compound can thereby bestably present on the surfaces of the water-absorbing polymer particles,even upon incorporation into cosmetics. The presence of such chemicalbonding can be confirmed by the fact that the silicone compound ispresent on the water-absorbing polymer particles even if thesilicon-modified polymer particles (10% by weight relative tochloroform) are subjected 3 times to a washing step of treating withchloroform for 2 hours under stirring (30 rpm, 50° C.) and thencentrifugal separation.

The water-absorbing polymer particles are preferably coated thereon withthe silicone compound to such an extent that the stickiness of thesurfaces of the water-absorbing swollen particles can be suppressed.

Assuming that the amount of the total polymer particles (including thesilicone compound) is 100 parts by weight, the lower limit of the amountof the silicone compound having at least one kind of functional group inthe water-absorbing polymer particles is preferably 0.1 part by weightor more, more preferably 0.5 part by weight or more, still morepreferably 1 part by weight or more. The upper limit is preferably 30parts by weight or less, more preferably 10 parts by weight or less,still more preferably 5 parts by weight or less.

To prevent gel blocking among polymer particles or sticky feeling duringuse, the silicone compound having at least one kind of functional groupis preferably hydrophobic. In particular, when the silicone compound isthe one having plural kinds of functional groups and having a functionalgroup not contributing to the reaction, the silicone compound ispreferably hydrophobic.

As used herein, the hydrophobic silicone compound having at least onekind of functional group refers to the one whose solubility in 100 gwater at 25° C. is not more than 10% by weight, preferably not more than1% by weight, more preferably not more than 0.5% by weight, even morepreferably not more than 0.1% by weight. The lower limit of thesolubility is not particularly present, but maybe not less than 0.01% byweight.

The weight average molecular weight of the silicone compound having atleast one kind of functional group is preferably 1000 to 500,000, morepreferably 3000 to 200,000 and particularly preferably 10,000 to200,000. Measurement of this weight average molecular weight isconducted by gel permeation chromatography (GPC), using polystyrene asstandard and chloroform as eluent.

The functional group is preferably at least one kind of functional groupselected from the group consisting of an amino group, an ammonium group,a carboxy group, a hydroxy group, an epoxy group and aradical-polymerizable unsaturated group, more preferably an amino groupand/or an ammonium group. These groups may be located at a side chain,one end and/or both ends of siloxane, or may be a mixture thereof.

Typical examples of the silicone compound having at least one kind offunctional group used in the present invention are shown below.

(1-1) Silicone compound having an amino group and/or an ammonium group(referred to hereinafter as amino-modified silicone)

The amino-modified silicone is preferably the one having a polymerizableunit represented by the following general formula (I):

wherein R¹ represents a hydrogen atom or a C₁₋₆ hydrocarbon group, and aplurality of R¹s maybe the same or different; R² represents R¹ or Xwhereupon X is a reactive functional group represented by —R³-Z (R³represents a direct bond or a C₁₋₂₀ divalent hydrocarbon group, and Zrepresents a primary to tertiary amino group-containing group or aquaternary ammonium group-containing group); and a is a number of 2 ormore, and b is a number of 1 or more.

In the general formula (I), R¹ groups independently represent a hydrogenatom or a C₁₋₆ hydrocarbon group, for example an alkyl group or phenylgroup, preferably a methyl group or ethyl group, more preferably amethyl group. R³ is preferably a C₁₋₆ linear or branched alkylene group,and includes a methylene group, ethylene group, trimethylene group,propylene group, tetramethylene group etc., more preferably atrimethylene group or propylene group a and b each represent the numberof polymerizing repeating units. Preferably, a is a number of 2 to 1000,and b is a number of 1 to 50. Z is preferably an amino group- orammonium group-containing group represented by the general formula (II)or (III) below.

wherein R⁴ represents

R⁵ and R⁶ each represent a hydrogen atom or a monovalent hydrocarbongroup, d and e each represent an integer of 0 to 6, and T⁻ represents ahalogen atom or an organic anion.

In the general formula (III), a plurality of R⁵s may be the same ordifferent. Specific examples of T⁻ include halogen ions such aschlorine, iodine, bromine etc. and organic anions such as methosulfate,ethosulfate, methophosphate, ethophosphate etc.

In the general formula (I), the group X is preferably —(CH₂)₃—NH₂,—(CH₂)₃—N(CH₃)₂—, —(CH₂)₃—NH—(CH₂)₂—NH₂, —(CH₂)₃—NH—(CH₂)₂—N(CH₃)₂, or—(CH₂)₃—N⁺(CH₃)₃Cl⁻, more preferably —(CH₂)₃—NH—(CH₂)₂—NH₂.

The weight average molecular weight of the amino-modified silicone ispreferably 3000 to 200,000, and for easy reaction with anionicfunctional groups of the water-absorbing polymer and for hydrophobicityof the silicone compound, the amine equivalent thereof is preferably 250to 10000 g/mol, more preferably 1000 to 5000 g/mol. That is, the amountof the amino group or ammonium group in the polymer is preferably 0.1 to4 mmol/g, more preferably 0.2 to 1 mmol/g. The amine equivalent can bemeasured in a solvent such as ethanol by titration with hydrochloricacid of known concentration.

(1-2) Silicon compound having a carboxy group (referred to hereinafteras carboxy-modified silicone)

The carboxy-modified silicone is preferably either a compound having asilicon atom and carboxy group bound via a saturated hydrocarbon, or anorganosiloxane compound having a carboxyl group and/or a salt thereofbound to a silicon atom via a structure shown in one of the formulae(IV) and (V), which is described in JP-A 2002-114849:

wherein R⁷, R⁸, R⁹ and R¹⁰ are the same or different and each representa C₂₋₂₂ linear or branched alkylene or alkenylene group or an arylenegroup, which may have a substituent group containing a heteroatom; Yrepresents an —O— or —NH— group; and M represents a hydrogen atom, ametal, ammonium, C₁₋₂₂ alkyl or alkenyl ammonium, C₁₋₂₂ alkyl oralkenyl-substituted pyridinium, C₁₋₂₂ alkanol ammonium, or a basic aminoacid.

Further, an amphoteric ionomer siloxane having two functional groupsi.e. a carboxyl group and an ammonium group described in JP-A 6-1711 canalso be preferably used.

The weight average molecular weight of the carboxy-modified silicone ispreferably 3000 to 200,000. For easy reaction with cationic functionalgroups of the water-absorbing polymer and for hydrophobicity of thesilicone compound, the carboxy equivalent thereof is preferably 250 to10000 g/mol, more preferably 1000 to 5000 g/mol. That is, the amount ofthe carboxy group in the polymer is preferably 0.1 to 4 mmol/g, morepreferably 0.2 to 1 mmol/g. The carboxy equivalent can be measured in asolvent such as ethanol by titration with NaOH of known concentration.

(1-3) Silicone compound having a hydroxyl group (referred to hereinafteras hydroxyl-modified silicone)

The hydroxy-modified silicone includes the branched silicone of thegeneral formula (VI), the both-terminal type silicone of the generalformula (VII), the one-terminal type silicone of the general formula(VIII), and an alkylglyceryl ether-modified silicone disclosed in JP-A5-112424.

wherein R¹¹ groups may be the same or different and each represent aC₁₋₃ alkyl group, preferably a methyl group; R¹² groups may be the sameor different and each represent a C₁₋₈ alkylene group, preferably atrimethylene group; AO groups may be the same or different and eachrepresent an ethyleneoxy group or propyleneoxy group; f and g each arean integer of 1 or more; and h is an integer of 0 or 1 or more.(1-4) Silicone compound having an epoxy group (referred to hereinafteras epoxy-modified silicone)

The epoxy-modified silicone is preferably a silicone compound containingan epoxy group at one and/or both ends represented by the generalformula (IX):

wherein R¹³ groups are the same or different and each represent amonovalent hydrocarbon group; R¹⁴ represents an epoxy-containing groupor a monovalent hydrocarbon group; A represents an epoxy-containinggroup; and n is a number of 1 to 10000.

The monovalent hydrocarbon group represented by R¹³ includes an alkylgroup such as methyl group and ethyl group, a cycloalkyl group such ascyclohexyl group, an aryl group such as phenyl group, and a fluorineatom-substituted alkyl group such as trifluoropropyl group. All R¹³groups may be the same or different, but all R¹³ groups are desirablymethyl groups.

In the general formula (IX), the epoxy-containing group represented by Ais not particularly limited, and specific examples include the groupsshown in the general formulae (X) to (XII):

wherein p and q each are an integer of 1 or more.

wherein r is an integer of 1 or more, and AO groups whose number is rare the same or different and each represent an ethyleneoxy group orpropyleneoxy group.

In the general formula (IX), when R¹⁴ represents the same group as inR¹³, the compound is silicone containing an epoxy group at one end,while when R¹⁴ represents the same group as in A, the compound issilicone containing an epoxy group at both ends.

The epoxy-modified silicone is preferably silicone containing an epoxygroup at one end, that is, silicone wherein R¹⁴ is the same group as inR¹³, wherein the hydrocarbon group is preferably an alkyl group such asmethyl group and ethyl group, a cycloalkyl group such as cyclohexylgroup, an aryl group such as phenyl group, and a fluorineatom-substituted alkyl group such as trifluoropropyl group, morepreferably a methyl group.

In the general formula (IX), n is preferably 1 to 500, more preferably 5to 100 and particularly preferably 10 to 50.

(1-5) Silicone compound having a radical polymerizable unsaturated group

Preferable examples of the silicone compound having a radicalpolymerizable unsaturated group include a polysiloxane compound having aradical polymerizable group at one end described in JP-A 11-181003.

(2) Surface-hydrophobated water-absorbing polymer particles wherein thesurfaces of water-absorbing polymer particles were coated with a polymerof a hydrophobic vinyl monomer

The surface-hydrophobated water-absorbing polymer particles arewater-absorbing polymer particles wherein the surfaces ofwater-absorbing polymer particles were coated with a polymer of at leastone kind of hydrophobic vinyl monomer.

At least a part of the surfaces of the water-absorbing polymer particlesis coated to such an extent as to suppress the stickiness of thesurfaces of the water-absorbing swollen particles.

The lower limit of the amount of the polymer of hydrophobic vinylmonomers in the surface-hydrophobated water-absorbing polymer particlesis preferably 1 weight part or more, more preferably 5 weight parts ormore, particularly preferably 10 weight parts or more, relative to 100parts by weight of the water-absorbing polymer particles. The upperlimit is preferably 1000 weight parts or less, more preferably 400weight parts or less, particularly preferably 200 weight parts or less.This range is preferable because there is no sticky feeling afterabsorption of water, and the speed of absorption of water is notparticularly inhibited.

The hydrophobic vinyl monomer used in the present invention is apolymerizable monomer giving a hydrophobic polymer by polymerization,and can be polymerized by a polymerization method with a general radicalpolymerization initiator or irradiation with ultraviolet light.

The hydrophobic vinyl monomer is a monomer having-the hydrophobicitydefined above, and a usual radical polymerizable hydrophobic vinylmonomer is preferably used. Examples of the monomer include, forexample, styrene, acrylates such as vinyl acetate, divinyl benzene,butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, decylacrylate, lauryl acrylate, dodecenyl acrylate, myristyl acrylate,palmityl acrylate, hexadecenyl acrylate, stearyl acrylate, octadecenylacrylate, behenyl acrylate etc., methacrylates such as butylmethacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, decylmethacrylate, lauryl methacrylate, dodecenyl methacrylate, myristylmethacrylate, palmityl methacrylate, hexadecenyl methacrylate,stearylmethacrylate, octadecenylmethacrylate, behenyl methacrylate etc.,fluorine-based monomers such as trifluoroethyl methacrylate, siliconemacromonomers etc. These hydrophobic monomers can be used as a mixtureof one or more thereof. Among these monomers, styrene and alkyl(meth)acrylates having a C₁₋₂₂ alkyl group are highly hydrophobic,easily available and preferable.

The weight average molecular weight of the hydrophobic polymer used inthe present invention is preferably 1000 to 500,000, more preferably3000 to 200,000 and particularly preferably 10,000 to 200,000.Measurement of this weight average molecular weight is conducted by gelpermeation chromatography (GPC), using polystyrene as standard. Thecolumn used was Shodex KF-806 manufactured by Showa Denko K.K.

To improve the adhesion of the formed polymer to the water-adsorbingpolymer, the hydrophilic vinyl monomer may be copolymerized to such anextent that the hydrophobicity of the resulting polymer is not extremelyinhibited.

Such hydrophilic vinyl monomer includes α,β-unsaturated carboxylic acidssuch as (meth)acrylic acid, maleic acid, itaconic acid etc., maleicanhydride, chloromethyl styrene, glycidyl(meth)acrylate,(meth)acryloyloxyethyl isocyanate,3-(trimethoxysilyl)propyl(meth)acrylate,dimethylaminoethyl(meth)acrylate, hydroxyethyl(meth)acrylate, vinylpyridine, (meth)acrylamide etc. These hydrophilic vinyl monomers can beused as a mixture of two or more thereof. The amount of the hydrophilicvinyl monomer used is preferably 0 to 50 weight %, more preferably 0 to20 weight %, of the total monomers constituting the polymer of thehydrophobic vinyl monomer.

(3) Surface-hydrophobated water-absorbing polymer particles wherein thesurfaces of water-absorbing polymer particles were treated with afluorine-based surfactant

A hydrophilic moiety of the fluorine-based surfactant can be any of fourkinds of moieties, that is, anionic, nonionic, cationic and amphoteric,while a hydrophobic moiety of the surfactant can make use of afluorocarbon chain or a perfluorocarbon chain. The fluorine-basedsurfactant preferably has a functional group capable of reacting withthe surfaces of the water-absorbing particles, and the hydrophobicmoiety is preferably anionic, cationic or amphoteric, more preferablycationic or amphoteric. The carbon chain in the hydrophobic moiety maybe a linear or branched chain. For example, the following fluorine-basedsurfactants can be mentioned.

Fluoroalkyl (C₂ to C₁₀) carboxylic acids, disodium N-perfluorooctanesulfonyl glutamate, sodium 3-[fluoroalkyl (C₆ to C₁₁)oxy]-1-alkyl (C₃ toC₄) sulfonate, sodium 3-[ω-fluoroalkanoyl (C₆ toC₈)-N-ethylaminol-1-propane sulfonate,N-[3-(perfluorooctanesulfonamide)propyl]-N,N-dimethyl-N-carboxymethyleneammonium betaine, fluoroalkyl (C₁₁ to C₂₀) carboxylic acid,perfluoroalkyl carboxylic acid (C₇ to C₁₃), perfluorooctane sulfonicacid diethanol amide, perfluoroalkyl (C₄ to C₁₂) sulfonates (Li, K, Na),N-propyl-N-(2-hydroxyethyl)perfluorooctane sulfonamide, perfluoroalkyl(C₆ to C₁₀) sulfonamide propyl trimethyl ammonium salt, perfluoroalkyl(C₆ to C₁₀)-N-ethyl sulfonyl glycine salt (K),bis(N-perfluorooctylsulfonyl-N-ethylaminoethyl)phosphate,monoperfluoroalkyl (C₆ to C₁₆) ethyl phosphate, perfluoroalkylquaternary ammonium iodide (trade name: Florade FC-135, a cationicfluorine-based surfactant manufactured by Sumitomo 3M Ltd.),perfluoroalkyl alkoxylate (trade name: Florade FC-171, a nonionicfluorine-based surfactant manufactured by Sumitomo 3M Ltd.) andpotassium perfluoroalkyl sulfonates (trade names: Florade FC-95 andFC-98, anionic surfactants manufactured by Sumitomo 3M Ltd.).

(4) Surface-hydrophobated water-absorbing polymer particles wherein thesurfaces of water-absorbing polymer particles were treated with a silanecoupling agent

As the silane coupling agent, a silane coupling described in JP-A61-211305 can be used.

Preferable examples include γ-glycidoxy propyl trimethoxy silane,γ-glycidoxy propyl methyl diethoxy silane, γ-(2-aminoethyl)aminopropyltrimethoxy silane, γ-(2-aminoethyl)aminopropyl methyl diethoxy silane,γ-aminopropyl triemethoxy silane, γ-chloropropyl trimethoxy silane,γ-chloropropyl methyl dimethoxy silane etc.

[Method of Producing Water-Absorbing Polymer Particles]

(1) Method of producing water-absorbing polymer particles bypolymerizing a hydrophilic vinyl monomer

When a polymer of a hydrbphilic vinyl monomer is used in thewater-absorbing polymer, the hydrophilic vinyl monomer and crosslinkingagent may be polymerized by any method, but a method of polymerizing anaqueous solution of the hydrophilic vinyl monomer (preferably at aconcentration of 1 to 70% by weight) is preferable, and various methodssuch as aqueous solution polymerization, reverse phase suspensionpolymerization and pearl polymerization can be used. In particular,aqueous solution polymerization or reverse phase suspensionpolymerization is preferable in respect of operativeness forpolymerization and the water-absorbing performance of the resultantwater-absorbing polymer, and reverse phase suspension polymerization isparticularly preferable in respect of higher water-absorbing performanceof the water-absorbing polymer. The temperature for polymerization ofthe hydrophilic vinyl monomer is preferably 20 to 120° C. and thepolymerization time is preferably 20 to 180 minutes.

As the polymerization initiator, a water-soluble radical polymerizationinitiator, for example a peroxide, hydroperoxide or an azo compound isknown in a known amount. These polymerization initiators can be used asa mixture of at least two kinds thereof, or can be used as redox typepolymerization initiators by adding chromium ion, sulfite,hydroxylamine, hydrazine etc. thereto. If necessary, an oil-solubleradical polymerization initiator, for example a peroxide type initiatorsuch as benzoyl peroxide, lauroyl peroxide, tert-butyl peroxy pivalateor diisopropyl peroxy dicarbonate, or an azo type initiator such asazobis(isobutyronitrile), azobis(2,4-dimethylvaleronitrile),azobis(dimethyl isobutyrate) or azobis(cyclohexane carbonitrile) canalso be used.

The amount of the water-soluble polymerization initiator is preferably0.03 to 5 weight %, more preferably 0.1 to 2 weight %, based on theamount of the hydrophilic vinyl monomer.

A dispersant is used to disperse and stabilize the hydrophilic vinylmonomer stably in the oil phase (solvent) The dispersant includes ageneral anionic, cationic, nonionic or amphoteric surfactant or anatural, semi-synthetic or synthetic polymer. Examples thereof includean anionic surfactant such as sodium polyoxyethylene dodecyl ethersulfate and sodium dodecylether sulfate, a cationic or amphotericsurfactant such as trimethylstearylammonium chloride andcarboxymethyldimethylcetyl ammonium, a sucrose fatty ester such assucrose monostearate and sucrose dilaurate, a sorbitan ester such assorbitan monostearate, a nonionic surfactant such as polyoxyalkyleneadducts of sorbitan esters, such as polyoxyethylenesorbitanmonostearate, a natural or semi-synthetic polymer such as cellulosederivatives such as starch or derivatives thereof, cellulose ethers suchas ethyl cellulose and cellulose esters such as cellulose acetate, and asynthetic polymer such as polyvinyl alcohol or derivatives thereof,maleic group-containing polybutadiene and a quaternary salt ofstyrene-dimethylaminoethyl methacrylate.

To produce the surface-hydrophobated water-absorbing polymer particles,the silicone compound having at least one kind of functional group orthe fluorine-based surfactant is preferably used as the dispersant. Itmay be combined with the other dispersant described above. Among thesilicone compounds, the dispersant is preferably a silicone compoundhaving at least one kind of functional group selected from the groupconsisting of an amino group, an ammonium group, a hydroxy group and acarboxy group.

The dispersant is present in an amount of preferably 0.5 to 30 parts byweight, more preferably 1 to 10 parts by weight, still more preferably 1to 7 parts by weight, relative to 100 parts by weight of the total vinylmonomers constituting the water-absorbing polymer particles.

The solvent used in reverse phase suspension polymerization ispreferably a hydrocarbon type solvent or silicone type solvent or amixture thereof. Examples of the hydrocarbon type solvent includealiphatic hydrocarbons such as hexane, heptane, dodecane, cyclohexane,methyl cyclohexane, isooctane and hydrogenated triisobutylene andaromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene, and examples of the silicone type solvent include octamethylcyclotetrasiloxane, decamethyl cyclopentasiloxane, hexamethyl disiloxaneand octamethyl trisiloxane. Among these solvents, hexane and cyclohexaneare particularly preferable.

Before water or solvent in the reaction system is distilled away afterpolymerization, the surface of particle may be crosslinked by adding acrosslinking agent later and reacting it by heating preferably at 40 to150° C.

(2) Method of producing surface-hydrophobated water-absorbing polymerparticles from water-absorbing polymer particles

The surface-hydrophobated water-absorbing polymer particles can beproduced from water-absorbing polymer particles after polymerization orfrom previously obtained water-absorbing polymer particles such as anaturally occurring polymer.

The method is preferably a production method which includes heatingwater-absorbing particles and a silicone compound having at least onekind of functional group in the presence of a fluorine-based surfactantor a silane coupling agent, in the presence of water preferably asolvent, to which a crosslinking agent and/or a radical polymerizationinitiator is added if necessary. By the presence of water, functionalgroups in the water-absorbing polymer particles are dissociated to reactreadily with functional groups in the silicone compound having at leastone kind of functional group, in the fluorine-based surfactant or in thesilane coupling agent. The amount of the silicone compound having atleast one kind of functional group, the fluorine-based surfactant or thesilane coupling agent is preferably 0.001 part by weight or more, morepreferably 0.01 part by weight or more, particularly preferably 0.1 partby weight or more, relative to 100 parts by weight of thewater-absorbing polymer (particles), and the upper limit is preferably20 parts by weight or less, more preferably 10 parts by weight or less,particularly preferably 5 parts by weight or less.

As the solvent, the above-mentioned hydrocarbon type solvent or siliconetype solvent or a mixture thereof is preferably used. The amount ofwater in the reaction system is preferably 1 to 200 parts by weight,more preferably 10 to 100 parts by weight, relative to 100 parts byweight of the water-absorbing polymer (particles). After the reaction,the water is removed, for example, by distillation. When thecrosslinking agent is used, the crosslinking agent is allowed to bepresent in an amount of preferably 0.01 to 10 parts by weight, morepreferably 0.01 to 5 parts by weight, still more preferably 0.01 to 3parts by weight, relative to 100 parts by weight of the water-absorbingpolymer (particles).

When the silicone compound having a radically polymerizable unsaturatedgroup is used, the above-mentioned oil-soluble radical polymerizationinitiator is preferably allowed to be coexistent. The silicone compoundhaving at least one kind of functional group or the fluorine-basedsurfactant can be added directly or as a solution wherein the siliconecompound or the fluorine-based surfactant has been solubilized ordispersed by emulsification in an organic solvent, a surfactant or adispersant, or in the form of a spray depending on the case. Heating forfacilitating surface treatment is preferably in the range of 40 to 150°C.

The silicone compound having at least one kind of functional group, thefluorine-based surfactant or the silane coupling agent may be mixed withthe water-absorbing polymer before or after disruption of the polymer,but it is more preferable that the water-absorbing polymer is disruptedto form water-absorbing polymer particles whose water content isregulated in a suitable range by drying if necessary, and thewater-absorbing polymer particles are mixed, in e.g. a kneader, withthem.

The water-absorbing polymer particles coated with the polymer of thehydrophobic vinyl monomer is preferably the one obtained by adding thehydrophobic vinyl monomer and the above-mentioned oil-solublepolymerization initiator to a reverse phase suspension polymerizationsolution during or after polymerization of the water-absorbing polymerparticles, that is, slurry having the water-absorbing polymer particlesdispersed in a solvent, followed by polymerizing the monomer. Thesolvent is preferably the above-mentioned hydrocarbon type solvent orsilicone type solvent or a mixture thereof.

The amount of the water-soluble polymerization initiator is preferably0.03 to 5% by weight, more preferably 0.1 to 2% by weight, based on theamount of the hydrophobic vinyl monomer. The polymerization initiator ispreviously mixed with other components and used as a solution, and forthe purpose of reducing the remaining monomer, it may be diluted with asolvent etc. during polymerization and added all at once orcontinuously. The polymerization temperature is preferably 20 to 120°C., and the polymerization time is preferably 20 to 180 minutes.

The surface-hydrophobated water-absorbing polymer particles used in thepresent invention are preferably those obtained by polymerization of ahydrophilic vinyl monomer and a crosslinking agent in the presence of asilicone compound having at least one kind of functional group or afluorine-based surfactant by a reverse phase suspension polymerizationmethod, those obtained by heating water-absorbing polymer particles, asilicone compound having at least one kind of functional group, afluorine-based surfactant or a silane coupling agent, in the presence ofwater, and those obtained by reverse phase suspension polymerization ofa hydrophilic vinyl monomer and a crosslinking agent in the presence ofa water-soluble polymerization initiator and a dispersant, and during orafter polymerization, adding a hydrophobic vinyl monomer and anoil-soluble polymerization initiator, followed by polymerizationthereof.

[Anti-Perspiring Component]

Preferable examples of the anti-perspiring component include aluminumcompounds, zirconium compounds, zinc compounds and mixtures thereof.Preferable examples include their sulfates, bromides, chlorides,chlorohydroxides, lactates etc., specifically aluminum salts such asallantoin chlorohydroxy aluminum, aluminum chloride, chlorohydroxyaluminum, allantoin dihydroxy aluminum, aluminum sulfate, potassium alumand aluminum hydroxide, aluminum-zirconium complexes such as aluminumzirconium tetrachlorohydroxy glycine and aluminum zirconiumpentachlorohydrate, and zinc salts such as zinc oxide and zinc p-phenolsulfonate. Among these, the aluminum compounds and zirconium compoundsare preferable, the aluminum salts and aluminum-zirconium complexes aremore preferable, and the aluminum-zirconium complexes are particularlypreferable.

[Silicone]

Preferably, the cosmetic composition of the present invention furthercontains silicone to improve smoothness during application and shaving.As the viscosity (25° C.) of such silicone is increased by using it in alarger amount, oily feeling is caused, so that in respect of feeling inuse, the viscosity is preferably not higher than 5×10⁻³ m²/S, morepreferably not higher than 5×10⁻⁴ m²/s, still more preferably not higherthan 5×10⁻⁵ m²/s and even more preferably not higher than 2×10⁻⁵ m²/s.The lower limit is preferably not lower than 1×10⁻⁶ m²/s.

Specific examples of silicone include linear silicones such aslow-polymerized dimethyl polysiloxane and cyclic silicones such asoctamethyl cyclotetrasiloxane, decamethyl cyclopentasiloxane etc., andone or more of these silicones can be suitably selected and used.

[Hydrophobic Particles]

The cosmetic composition of the present invention preferably containshydrophobic particles to further improve smoothness upon shaving and dryfeeling on the skin.

Preferable examples of the hydrophobic particles include fine polymerparticles obtained by suspension polymerization of a vinyl monomer in asolvent with a polysiloxane compound having a radical-polymerizablegroup at one end as a dispersant, that is, silicone-based resin such assilicone resin (KMP-590 (manufactured by Shin-Etsu Chemical Co., Ltd.)),Tospearl 145, Tospearl 2000B (manufactured by GE Toshiba Silicones Co.,Ltd.), Torefil (manufactured by Toray Industries, Inc.) etc.;fluorine-based resin; particles obtained by subjecting organic powdersuch as nylon resin (SP-500 (manufactured by Toray Industries, Inc.)etc.), polystyrene-based resin (Fine Pearl (manufactured by SumitomoChemical Co., Ltd.), Techno Polymer SB (manufactured by Sekisui PlasticsCo., Ltd.), Fine Powder SGP (manufactured by Soken Chemical &Engineering Co., Ltd.) etc.), polyethylene resin (Flow Beads(manufactured by Sumitomo Seika Co., Ltd.) etc.), polymethylmethacrylate-based resin (Matsumoto Microsphere M (manufactured byMatsumoto Oil and Fat Co., Ltd.), Tech Polymer MB (manufactured bySekisui Plastics Co., Ltd.), Fine Powder MP (manufactured by SokenChemical & Engineering Co., Ltd.) etc.), divinyl benzene-based resin,polyurethane-based resin, benzoguanamine resin, melamine resin, orphenol-based resin, to hydrophobation treatment such as siliconetreatment (for example, treatment with methyl hydrogen polysiloxane ordimethyl polysiloxane), fluorine treatment, metallic soap treatment orfatty acid treatment, preferably silicone treatment or fluorinetreatment; and particles obtained by subjecting inorganic powder such astalc, sericite, mica, kaolin, red oxide, clay, bentonite, silicicanhydride, biotite or synthetic silica beads, to hydrophobationtreatment such as silicone treatment (for example, treatment with methylhydrogen polysiloxane or dimethyl polysiloxane), fluorine treatment,metallic soap treatment or fatty acid treatment, preferably siliconetreatment or fluorine treatment.

The shape of the hydrophobic particles may be in the form of sphere,tube, plate or needle, preferably in the form of sphere in respect ofsmoothness. The roundness of the hydrophobic particles is notparticularly limited, but as the roundness is increased, the dynamiccoefficient of friction is decreased to improve smoothness on the skin,and thus hydrophobic particles that are as round as possible arepreferably used. The average particle diameter of the hydrophobicparticles is preferably 0.05 to 50 μm, particularly preferably 0.5 to 50μm.

[Cosmetic Composition]

The cosmetic composition of the present invention may be any ofemulsified cosmetics, oil cosmetics, spray cosmetics, stick-typecosmetics, powdered cosmetics and roll-on type cosmetics, and is usedpreferably for antiperspiration.

The cosmetic composition of the present invention containswater-absorbing polymer particles, preferably surface-hydrophobatedwater-absorbing polymer particles. The content (content in a state notswollen with water) of the water-absorbing polymer particles in thecomposition is preferably 0.1 to 90% by weight, more preferably 0.5 to50% by weight, still more preferably 1 to 20% by weight and even morepreferably 2 to 10% by weight. The polymer particles in this range arepreferable because they can suppress stickiness after absorption ofsweat. Further, the surface-hydrophobated water-absorbing polymerparticles are used preferably as water-absorbing polymer particles inorder to maintain the dry feel of the particles after absorption ofsweat to enable smooth shaving.

The content of the anti-perspiring component in the cosmetic compositionof the present invention is preferably 0.1 to 90% by weight, morepreferably 1 to 70% by weight, still more preferably 5 to 50% by weightand even more preferably 10 to 30% by weight. The polymer particles inthis range are preferable because of their high anti-perspiring effect.

The amount of the water-absorbing polymer particles is preferably 3 to95 parts by weight, more preferably 3 to 50 parts by weight, based on100 parts by weight of the anti-perspiring component. The particles inan amount in this range are preferable because the deterioration insmoothness upon shaving caused by precipitation of an aluminum salt canbe solved by simultaneously using the water-absorbing polymer particlesin the above range, and both the components can be maintained atsuitable pH value at the time of perspiring.

The content of silicone having a viscosity (25° C.) of not higher than5×10⁻³ m²/s in the cosmetic composition of the present invention ispreferably 0.1 to 90% by weight, more preferably 0.5 to 50% by weight,still more preferably 1 to 20% by weight and even more preferably 2 to10% by weight.

The content of the hydrophobic particles in the cosmetic composition ofthe present invention is preferably 0.5 to 30% by weight, morepreferably 0.5 to 20% by weight, still more preferably 0.5 to 10% byweight and even more preferably 1 to 5% by weight.

Particularly, when usual water-absorbing polymer particles whose surfaceis not hydrophobated are used, at least one member selected from thegroup consisting of silicone having a viscosity (25° C.) of not higherthan 5×10⁻³ m²/s and hydrophobic particles is preferably used in orderto improve smoothness in shaving.

Depending on the form, type etc. of the cosmetic composition of thepresent invention, other generally used cosmetic components can befurther incorporated into the cosmetic composition in such a range thatthe effect of the present invention is not hindered.

Such cosmetic components include e.g. extender pigments such as mica,talc, sericite, kaolin, polymethylsilyl sesquioxane and barium sulfate;inorganic pigments such as titanium oxide, zinc white and iron oxide;hydrocarbons such as solid or liquid paraffin, solid paraffin,microcrystalline wax, vaseline, ceresin, ozokerite and montan wax;vegetable or animal fats and oils or wax, such as olive, ozokerite,carnauba wax, lanoline and spermaceti; fatty acids or esters thereofsuch as stearic acid, palmitic acid, oleic acid, glycerine monostearate,glycerine distearate, glycerine monooleate, isopropyl myristate,isopropyl stearate and butyl stearate; higher alcohols such as cetylalcohol, stearyl alcohol, palmityl alcohol and hexyl dodecyl alcohol;adsorbents or thickening agents such as cationic cellulose,carboxybetaine type polymer and cationic silicone; polyhydric alcoholshaving a moisture retention action, such as glycol and sorbitol;efficacious components such as whitening agent, analgesicantiinflammatory agents, anti-itching agents, astringents, skinsoftening agents and hormones; water; surfactants; W/O or O/W typeemulsifying agents; emulsifying agents for silicone oil, such aspolyether-modified silicone, polyether alkyl-modified silicone andglyceryl ether-modified silicone; thickening agents such as methylcellulose, ethyl cellulose, carboxymethyl cellulose, polyacrylic acid,tragacanth, agar and gelatin; lower alcohols such as ethanol, glycerin,1,3-butylene glycol and propylene glycol; and other components such asemulsion stabilizers, chelating agents, UV protecting agents, pHadjusting agents, preservatives, coloring matters and perfumes.

The cosmetics of the present invention are produced according to aconventional method.

The cosmetic composition of the present invention exhibits a highanti-perspiring effect to enable further smooth shaving. Particularly,the surface-hydrophobated water-absorbing polymer particles can be usedto give highly dry feel even after perspiring.

EXAMPLES

In the following examples, “%” refers to “% by weight” unless otherwisespecified.

Synthesis Example 1

300 g methacrylic acid (Mitsubishi Rayon Co., Ltd.) and 135 gion-exchange water were placed in a 3-L beaker and then neutralized to adegree of 75% by adding 348 g of 30% aqueous sodium hydroxide solutiondropwise thereto under cooling with stirring, and then a solution of 1.2g potassium persulfate (0.4% relative to methacrylic acid) dissolved in24.3 g ion-exchange water and a crosslinking agent ethylene glycoldiglycidyl ether (trade name, Denacol EX810, Nagase Kasei Co., Ltd.),15.0 g (5.0% relative to methacrylic acid), were added thereto, and themixture was uniformly dissolved. The resultant solution was added to asolution obtained by dissolving 15 g amino-modified silicone A (XF42-703produced by GE Toshiba Silicones Co., Ltd.; viscosity (25° C.), 1×10⁻³m²/s; amine equivalent, 1500 g/mol) in 1500 ml cyclohexane in a 3-Lbeaker, and the mixture was stirred vigorously for 5 minutes at a numberof revolutions of 10000 rpm in a homomixer to produce a finewater-in-oil droplet dispersion. Then, 900 ml cyclohexane was introducedinto a 5-L stainless steel reaction vessel equipped with a refluxcondenser, then stirred at 350 rpm, and heated at 75° C. in the system,and the atmosphere was replaced by nitrogen, followed by dropwiseaddition of the partially neutralized water-in-oil droplet dispersion ofmethacrylic acid to initiate polymerization. The whole of the dropletdispersion was added dropwise over 1.5 hours, and the reaction solutionwas aged for additional 4 hours at the reflux temperature. Thereafter, adehydration tube was attached, the temperature was raised to remove 340ml water, and the reaction solution was cooled and filtered to separatepolymer particles. By evaporation into dryness under reduced pressure,376 g dry white polymer in the form of fine powder was obtained. Theaverage particle diameter of the resultant fine polymer particles was2.2 μm, and the amount of water absorbed was 15 g/g.

Synthesis Example 2

180 g aqueous solution of a neutralized product (effective component,90%) of dimethylaminoethyl methacrylate with diethylsulfuric acid, 120 gN,N-dimethylacrylamide, 14 g polyethylene glycol dimethacrylate (tradename: NK-14G, manufactured by ShinNakamura Chemical Co., Ltd.), 5 gmethacrylic acid, 415 g ion-exchange water and 1.2 g potassiumpersulfate were introduced into a 3-L beaker and dissolved uniformly.The obtained solution was added to a solution obtained by dissolving 15g amino-modified silicone A (XF42-703 produced by GE Toshiba SiliconesCo., Ltd.; viscosity (25° C.), 1×10⁻³ m²/s; amine equivalent, 1500g/mol) in 1500 ml cyclohexane in a 3-L beaker. The mixture was stirredvigorously for 5 minutes at a number of revolutions of 10000 rpm in ahomomixer to produce a fine water-in-oil droplet dispersion. Thewater-in-oil droplet dispersion was introduced into a 5-L stainlesssteel reaction vessel equipped with a reflux condenser and then stirredat 350 rpm. Purged by nitrogen gas, it was heated at 75° C. and it waskept for 4 hours for polymerization. Thereafter, a dehydration tube wasattached, the temperature was raised to remove 340 ml water and thereaction solution was cooled and filtered to separate polymer particles.By evaporation into dryness at a reduced pressure, 280 g dry whitepolymer in the form of fine powder was obtained. The average particlediameter of the resultant fine polymer particles was 2.5 μm, and theamount of water absorbed was 18 g/g.

Synthesis Example 3

300 g N,N-dimethylacrylamide, 4.5 g polyethylene glycol dimethacrylate(trade name: NK-14G, manufactured ShinNakamura Chemical Co., Ltd.), 5 gmethacrylic acid, 400 g ion-exchange water and 1.2 g potassiumpersulfate were introduced into a 3-L beaker and dissolved uniformly.The obtained solution was added to a solution obtained by dissolving 15g amino-modified silicone A (XF42-703 produced by GE Toshiba SiliconesCo., Ltd.; viscosity (25° C.), 1×10⁻³ m²/s; amine equivalent, 1500g/mol) in 1500 ml of cyclohexane in a 3-L beaker. The mixture wasstirred vigorously for 5 minutes at a number of revolutions of 10000 rpmin a homomixer to produce a fine water-in-oil droplet dispersion. Thewater-in-oil droplet dispersion was introduced into a 5-L stainlesssteel reaction vessel equipped with a reflux condenser and then stirredat350rpm. Purged by nitrogen gas, it was heated at 75° C. and it waskept for 4 hours for polymerization. Thereafter, a dehydration tube wasattached, the temperature was raised to remove 340 ml water and thereaction solution was cooled and filtered to separate polymer particles.By evaporation into dryness at a reduced pressure, 290 g dry whitepolymer in the form of fine powder was obtained. The average particlediameter of the resultant fine polymer particles was 2.3 μm, and theamount of water absorbed was 18 g/g.

Synthesis Example 4

300 g methacrylic acid (Mitsubishi Rayon Co., Ltd.) and 135 gion-exchange water were placed in a 3-L beaker and neutralized to adegree of 75% by adding 348 g of 30% aqueous sodium hydroxide solutiondropwise thereto under cooling with stirring, and then a solution of 1.2g potassium persulfate (0.4% relative to methacrylic acid) dissolved in24.3 g ion-exchange water, and 15.0 g of a crosslinking agent ethyleneglycol diglycidyl ether (trade name, Denacol EX810, Nagase Kasei-Co.,Ltd.) (5.0% relative to methacrylic acid), were added thereto, and themixture was uniformly dissolved. The resultant solution was added to asolution obtained by dissolving 15 g sugar esters (a mixture of RyotoSugar Esters S570 and S770 (trade name) in equal amounts, MitsubishiShokuhin Co., Ltd.) (5.0% relative to methacrylic acid) in 1500 mlcyclohexane in a 3-L beaker, and the mixture was stirred vigorously for5 minutes at a number of revolutions of 10000 rpm in a homomixer toproduce a fine water-in-oil droplet dispersion. Then, 900 ml cyclohexanewas introduced into a 5-L stainless steel reaction vessel equipped witha reflux condenser, then stirred at 350 rpm, and heated at 75° C. in thesystem, and the atmosphere was replaced by nitrogen, followed bydropwise addition of the partially neutralized water-in-oil dropletdispersion of methacrylic acid to initiate polymerization. The whole ofthe droplet dispersion was added dropwise over 1.5 hours, and thereaction solution was aged for additional 4 hours at the refluxtemperature. Thereafter, a dehydration tube was attached, thetemperature was raised to remove 340 ml water, further 1300 mlcyclohexane was distilled away, and the reaction solution was left andcooled to complete synthesis. By evaporation into dryness under reducedpressure, 376 g dry white polymer in the form of fine powder wasobtained. The average particle diameter of the resultant fine polymerparticles was 2.2 μm, and the amount of water absorbed was 12 g/g.

Examples 1 to 4 and Comparative Example 1

The water-absorbing polymer particles obtained in each of SynthesisExamples 1 to 4 were mixed uniformly under heating with all thecomponents shown in Table 1, and the resultant mixture was introducedinto a container, then left and cooled to give a stick-typeantiperspirant. The resultant antiperspirant was evaluated foranti-perspiring performance and smoothness and stress upon shaving. Theresults are collectively shown in Table 1.

<Method of Evaluating Anti-Perspiring Performance>

The test sample, 0.3 g, was applied onto one armpit, and 3 hours later,an examinee was allowed to be in a high-temperature high-humidity room(40° C./80% RH) for 5 minutes, and just after leaving the room, theexaminee herself evaluated anti-perspiring performance sensorily whenperspired. Subsequently, the degree of wetting on the armpit 3 hoursafter leaving the room was evaluated sensorily as anti-perspiringperformance in a normal state by the examinee herself under theconditions of 25° C./60% RH. The anti-perspiring performance wasevaluated in 5 ranks under the following criteria.

-   1: Evidently wet.-   2: Wet.-   3: Slightly wet.-   4: Dry.-   5: Evidently dry.    <Method of Evaluating Smoothness Upon Shaving>

Five hours after the above evaluation of anti-perspiring performance wasfinished, lather foamed from soap in a bathroom was applied onto thearmpit, and the armpit was shaved with a commercial razor, andsmoothness upon shaving was evaluated sensorily by the examinee herselfin 5 ranks under the following criteria:

-   1: Very poor in smoothness.-   2: Poor in smoothness.-   3: Slightly poor in smoothness.-   4: Excellent in smoothness.-   5: Very excellent in smoothness.    <Measurement of Stress Upon Shaving>

0.3 g of the test sample was applied onto one forearm, and soap made inthe US (DAVE manufactured by Unilever) was applied onto the forearm, andthe armpit was shaved with a commercial razor equipped with a stressmeter (Handy Force Gauge, manufactured by Nippon Keisoku System Co.,Ltd.), and the maximum stress (N) during shaving was measured. Themeasurement was conducted 6 times by each of 3 examinees, and theaverage value was indicated as stress (N) upon shaving. ExampleComparative example 1 2 3 4 1 Sweat- Water-absorbing polymer particlesin 8.0 0.0 0.0 0.0 0.0 regulating Synthesis example 1 agentWater-absorbing polymer particles in 0.0 8.0 0.0 0.0 0.0 (%) Synthesisexample 2 Water-absorbing polymer particles in 0.0 0.0 8.0 0.0 0.0Synthesis example 3 Water-absorbing polymer particles in 0.0 0.0 0.0 8.00.0 Synthesis example 4 Aluminum Zirconium 22.4 22.4 22.4 22.4 22.4tetrachlorohydrex gly*¹ Cyclomethicone, D5*² 43.2 43.2 39.2 39.2 43.2Talc 0.0 0.0 4.0 4.0 8.0 PPG-14 butyl ether*³ 2.8 2.8 2.8 2.8 2.8 C₁₂₋₁₅alkyl benzoate 3.7 3.7 3.7 3.7 3.7 Stearyl alcohol 15.0 15.0 15.0 15.015.0 Arachidyl alcohol 1.9 1.9 1.9 1.9 1.9 Hardened castor oil 3.0 3.03.0 3.0 3.0 Results of anti-perspiring performance 5 5 5 5 4 evaluation(in a normal state) anti-perspiring performance 5 4 5 4 3 (whenperspired) Stress upon shaving(N) 0.50 0.42 0.48 0.62 0.81 Smoothnessupon shaving 5 5 5 4 2Notes:*¹Reach AZP-908SUF manufactured by Reheis*²Decamethyl cyclosiloxane, SH-245, manufactured Dow Corning ToraySilicone Co., Ltd.*³Ucon ® Fluid AP manufactured by Amerchol Corporation.

Hereinafter, formulation examples are shown.

Formulation Example 1 Powdered Antiperspirant

<Composition> a) Aluminum zirconium pentachlorohydrate 15.0% b)Trichlosane 0.01 c) Water-absorbing polymer particles in SynthesisExample 1, 5.0 d) Talc balance e) Perfume suitable amount

Formulation Example 2 Aerosol Type Antiperspirant

<Composition> a) Aluminum zirconium pentachlorohydrate 8.0% b)Water-absorbing polymer particles in Synthesis Example 1 2.0 c) Acrylicpolymer particles* 1.0 d) Talc 0.5 e) Isopropyl palmitate 1.5 f) Perfume0.2 g) Isopentane 10.0 h) Liquefied petroleum gas balance*Matsumoto Microsphere M305 (particle diameter 7 μm) manufactured byMatsumoto Oil and Fat Co., Ltd.

Formulation Example 3 Non-Aqueous Roll-On Type Antiperspirant

<Composition> ′a) Octamethyl cyclotetrasiloxane 67.0% b) Dimethicone6cs* 5.0 c) Ethanol 5.0 d) Water-absorbing polymer particles inSynthesis Example 1 3.0 e) Aluminum zirconium pentachlorohydrate 20.0*KF96-6cs manufactured by Shin-Etsu Chemical Co., Ltd.

Formulation Example 4 Soft Solid Type Antiperspirant

<Composition> a) Octamethyl cyclotetrasiloxane 54.0% b) Behenyl alcohol6.0 c) Mineral oil*¹ 7.0 d) Water-absorbing polymer particles inSynthesis Example 1 3.0 e) Aluminum zirconium pentachlorohydrate 20.0 f)Alkyl-modified silicone*² 2.0 g) Cyclomethicone/dimethiconecrosspolymer*³ 1.5 h) Colloidal silica 2.5 i) Talc 4.0*¹DRAKEOL ® LT MINERAL OIL manufactured by N.F. Penreco*²TSF4421 manufactured by GE Toshiba Silicones Co., Ltd.*³KSG16 manufactured by Shin-Etsu Chemical Co., Ltd.

1. A cosmetic composition comprising surface-hydrophobatedwater-absorbing polymer particles and an anti-perspiring component. 2.The cosmetic composition according to claim 1, wherein thesurface-hydrophobated water-absorbing polymer particles comprisewater-absorbing polymer particles coated thereon with a siliconecompound having at least one kind of functional group.
 3. A cosmeticcomposition comprising water-absorbing polymer particles, ananti-perspiring component, and at least one member selected from thegroup consisting of silicone having a viscosity (25° C.) of not higherthan 5×10⁻³ m²/s and hydrophobic particles, the content of thewater-absorbing polymer particles being 3 to 95 parts by weight relativeto 100 parts by weight of the anti-perspiring component.
 4. The cosmeticcomposition of claim 1, wherein the average particle diameter of polymerparticles selected from the water-absorbing polymer particles and thesurface-hydrophobated water-absorbing polymer particles is 0.1 to 50 μm.5-8. (canceled)
 9. The cosmetic composition of claim 2, wherein theaverage particle diameter of polymer particles selected from thewater-absorbing polymer particles and the surface-hydrophobatedwater-absorbing polymer particles is 0.1 to 50 μm.
 10. The cosmeticcomposition of claim 3, wherein the average particle diameter of polymerparticles selected from the water-absorbing polymer particles and thesurface-hydrophobated water-absorbing polymer particles is 0.1 to 50 μm.11. The cosmetic composition of claim 1, wherein the amount of waterabsorbed into the polymer particles selected from the water-absorbingpolymer particles and the surface-hydrophobated water-absorbing polymerparticles is 5 to 100 g/g.
 12. The cosmetic composition of claim 2,wherein the amount of water absorbed into the polymer particles selectedfrom the water-absorbing polymer particles and the surface-hydrophobatedwater-absorbing polymer particles is 5 to 100 g/g.
 13. The cosmeticcomposition of claim 3, wherein the amount of water absorbed into thepolymer particles selected from the water-absorbing polymer particlesand the surface-hydrophobated water-absorbing polymer particles is 5 to100 g/g.
 14. The cosmetic composition of claim 4, wherein the amount ofwater absorbed into the polymer particles selected from thewater-absorbing polymer particles and the surface-hydrophobatedwater-absorbing polymer particles is 5 to 100 g/g.
 15. The cosmeticcomposition of claim 9, wherein the amount of water absorbed into thepolymer particles selected from the water-absorbing polymer particlesand the surface-hydrophobated water-absorbing polymer particles is 5 to100 g/g.
 16. The cosmetic composition of claim 10, wherein the amount ofwater absorbed into the polymer particles selected from thewater-absorbing polymer particles and the surface-hydrophobatedwater-absorbing polymer particles is 5 to 100 g/g.
 17. The cosmeticcomposition of claim 1, wherein the anti-perspiring component is atleast one member selected from the group consisting of an aluminumcompound, a zirconium compound and a zinc compound.
 18. The cosmeticcomposition of claim 2, wherein the anti-perspiring component is atleast one member selected from the group consisting of an aluminumcompound, a zirconium compound and a zinc compound.
 19. The cosmeticcomposition of claim 3, wherein the anti-perspiring component is atleast one member selected from the group consisting of an aluminumcompound, a zirconium compound and a zinc compound.
 20. The cosmeticcomposition of claim 4, wherein the anti-perspiring component is atleast one member selected from the group consisting of an aluminumcompound, a zirconium compound and a zinc compound.
 21. The cosmeticcomposition of claim 9, wherein the anti-perspiring component is atleast one member selected from the group consisting of an aluminumcompound, a zirconium compound and a zinc compound.
 22. The cosmeticcomposition of claim 11, wherein the anti-perspiring component is atleast one member selected from the group consisting of an aluminumcompound, a zirconium compound and a zinc compound.
 23. A method ofcontrolling perspiration, comprising applying a composition comprisingsurface-hydrophobated water-absorbing polymer particles and ananti-perspiring component onto the skin.